Is a 20 gallon tank ideal for angelfish?

In this blog we will discuss a 20 gallon tank for angelfish.This guide will help new angelfish keepers about setting up a 20 gallon tank for their angelfish.


In this blog

  • Is a 20 gallon tank ideal for angelfish?
  • Can you keep four angelfish in a 20 gallon tank?
  • Can you keep 2 angelfish in a 20 gallon tank?
  • Water parameters in angelfish tank
  • Do angelfish require filters in a 20 gallon tank?
  • Do angelfish require a heater in their 20 gallon tank?
  • Do angelfish require an air pump or blubbers in their 20 gallon tank?
  • Live plants in angelfish 20 gallons tank
  • Do angelfish like strong water currents in their tank? 
  • How often do you change water in an angelfish tank?
  • Can you breed angelfish in a 20 gallon tank?
  • Summary 
  • Frequently asked questions
  • Reference 

Is a 20 gallon tank ideal for angelfish?

Freshwater angelfish are said to be about 6 inches or 15.24 cm long, and fins can grow to 8 inches or 20.32 cm long.

They grow quickly at first, reaching four inches in six months, and they can take up to a year and sometimes even longer to mature to their full size.

The ideal tank size to keep a single angelfish is 29 gallons,but they can adjust in a 20 gallons tank,if tank maintenance is done properly from proper feeding schedule to water replacements.

Can you keep angelfish in a 20 gallon tank?

Angelfish are very large and require a tank of 55 gallons or more when fully grown.Tall aquariums are perfect for adapting their body shape.

Angelfish prefer slow water currents like their natural habitat,so the flow of water should be gentle and the decoration should include large hardwoods/driftwood arranged vertically to simulate fallen branches and trees.

If you’re lucky enough to have a pair out of the four, you can fit two into a 20-gallon tank.To do this, you need to implement a maintenance plan very consistently.

Putting four angels in a 20 gallon tank will not work in the long run and this will work until you have a breeding pair. 

Can you keep 2 angelfish in a 20 gallon tank?

You should house two angelfish in a 29 gallon aquarium as they grow bigger in size when they mature.

You can keep two or more angelfish in a 29-gallon aquarium or in a tank smaller than 29 gallons for example, 10-20 gallons.But you will have to change the water more often, perhaps even every other day.

Water parameters in angelfish tank

Pristine water conditions in angelfish tank:

  • Water pH should be between 6.8 and 7.8
  • Degree of water hardness should be between 3° and 8° dKH  or 54 to 145 ppm. 
  • Aquarium water temperature should be best kept between 78° and 84° F (slightly warmer water)

Do angelfish require filters in a 20 gallon tank?

Angelfish can live in a small aquarium that holds at least 20 gallons of water. Set the filter and the angelfish will swim gracefully.

Filters relieve stress on the fish and help them swim as they prefer to move against the flow.

Make sure the filter is strong enough to clean the fish droppings produced by the angelfish.

Many enthusiasts prefer the internal filters for angelfish aquarium.This is because they are one of the first choices for a small aquarium.

Cleaning the filter media is very easy and different types of media are used for the internal filters.

Mechanical and biological media can be used for the internal filter. No chemical filter media is required and can be avoided. Adjust the water flow rate of the filter according to the needs of the angelfish.

In the wild, angelfish live in slow-moving water, so generating high currents in an aquarium is not a good option. However, they like the flow of water and like to swim with them like any other fish.

The movement of water is beneficial to fish as it increases oxygen in the water and removes carbon dioxide and fish droppings.

Angelfish can live up to 12 hours without a filter. Also, if the aquarium is set up properly, it can last longer.However, if the aquarium is overcrowded and unsanitary, it may die 12 hours earlier.

Do angelfish require a heater in their 20 gallon tank?

Angelfish are tropical fish that require a heater because they require a temperature range of 78-84 Fahrenheit with minimal fluctuations. This allows them to thrive and breed.

However, if the room temperature is between 24-27 degrees Celsius, they will survive but may not grow as expected.On the other hand, low temperatures can slow the growth rate of fish.Therefore, they can die within a few weeks.

Aqueon Pro heaters feature a rugged, non-corrosive housing for durability and even heat distribution. They have electronic thermostats for precise temperature setting and safety.

The power LED indicator lights up red when the device is warming up and green when the selected temperature is set.

It can be used for freshwater or marine aquariums and can be positioned horizontally or vertically depending on preference.

  • Color black and gray
  • Brand Aqueon
  • Product dimensions LxWxH 4″ x 14″ x 2″ 
  • Product weight 0.6 lbs
  • Heat output 100W

Do angelfish require an air pump or blubbers in their 20 gallon tank?

An aerator is a device that adds oxygen to the water in an aquarium. Most angelfish tanks do not require a bubbler,as all angelfish require aeration,but angelfish require a true filter to provide adequate aeration.

They can very much live without air pumps or blubbers in their tank, if live plants are added in their tank,as live plants keeps the tank environment purified and oxygenated.If you are not adding live plants then it will be a problem.

Live plants in angelfish 20 gallons tank

Listing some of the best tank plants for angelfish tanks,as they like thick vegetation in their tank,so try replicating the same like their natural habitat in their tanks too.

Since it’s a 20 gallon tank,not an ideal size for angelfish,try not to stuff the tank with plants completely.Make sure to go ahead with one or two aquatic plants as a hiding spots for them for feeling secure and for resting purposes too.

You can choose any of these in a 20 gallon tank,make sure you are not stuffing the tank with plants completely.

  • Amazon Swords- (for a breeding pair of angelfish)
  • Water sprite 
  • Java Fern
  • Jungle vallisneria
  • Dwarf tiger lotus
  • Water wisteria
  • Hornwort
  • Ambulia

Do angelfish like strong water currents in their tank? 

Angelfish don’t like strong water currents in their tanks because they enjoy floating on the water very much like their natural habitat where they live in very slow-moving waters.

So,it is important to replicate the same water flow in their artificial tank by minimizing the current in the tank.

How often do you change water in an angelfish tank?

Angelfish are very sensitive to poor water quality.Its very important to monitor the water everyday with a good quality testing kit to check the levels of ammonia buildup,because if it is left unattended then it can affect their health.

They are also one of the fish that really really reacts to large and frequent changes in water.Frequently changing the water can stress them.It is recommended to perform a 10% weekly or 25% water change every other week.

It is also important to remove uneaten food from their tanks on a daily basis with the help of a gravel siphon without disturbing beneficial bacteria.

Can you breed angelfish in a 20 gallon tank?

Try to choose a tank of at least 20 gallons/75.7 liters, ideally 29 gallons/110 liters. If you have enough space, a pair of angelfish is best.20 gallon tall aquarium is the smallest aquarium to accommodate a pair of angelfish.

Angelfish need to feel safe to reproduce freely and successfully. Their natural environment is slowly flowing water with many hiding places such as roots and tall plants.


  • Angelfish are quite big in size and they grow very rapidly,so they cannot be kept in smaller tanks below 29 gallons.
  • A single angelfish can be housed in a 20 gallon tank.
  • Don’t overcrowd their tanks with other angelfish or different tank mates,this might stress them due to lack of space.
  • Keeping them in tanks smaller than 29 gallons will reduce their lifespan and body growth too.
  • Angelfish likes very small amounts of flow, so there is no need to generate strong current, a low flow aeration or an under gravel filter is best for them.
  • They like their space, even if they aren’t aggressive swimmers, in a 20 gallon tank, they are much more likely to fight and will damage each other when they fight.
  • They like tall tanks with live plants like their natural habitat.
  • Replicating the same water parameters,water flow and live plants will keep them happy and healthy and this in turn will increase their lifespan too.
  • Always bear this in mind,angelfish are not meant for smaller tanks,they grow quickly,and do well in bigger and spacious tanks with lots of swimming and hiding space.
  • If you want to add tank mates then get a bigger tank.Housing them in bigger tanks will reduce aggression,fights or food and space and even reduce their stress too.
  • Overcrowded tanks are one of the main reasons for various infections in aquarium species,so avoid housing them in compact tanks at all cost.
  • Never compromise with the tank size,water parameters and food quality for your aquatic friend ,if you want them to live longer.
  • Angelfish are beautiful and entertaining fish,it’s very important to keep them happy and healthy.Just keep their tanks clean and follow proper tank maintenance.Thats more than enough and bigger tanks don’t get dirty quickly as compared to smaller tanks.

Frequently asked questions

Do angelfish tanks need a substrate in their 20 gallon tank?

Mud or Fine sand will make the best substrate for angelfish tank.A fine substrate is preferred to enable safe digging.

Can we keep tank mates with angelfish in a 20 gallon tank?

No, you cannot keep angelfish with tank mates in a 20 gallon tank,because a single angelfish itself requires a 20-29 gallons tank.

How many angelfish can be kept together in a 20 gallon tank?

The ideal tank size for a fully grown single angelfish is 29 gallons,so it is not possible to accommodate more than one angelfish in a 20 gallon tank.